Sequential timer



Sept 11, 1962 J. BowMAN ETAL SEQUENTIAL TIMER 2 Sheets-Sheet 1 FiledJune 15, 1959 FIGLI Finali.

INVENTORS JOE BOWMAN L .W LEY BY EE A OOL WI ATTOR EYS` Sept. l1, 1962J. BOWMAN ETAL SEQUENTIAL TIMER Filed June l5, 1959 2 Sheets-Sheet 2FIGB s Ha

55 56 67 70a Hb 63 Fl G. 6

BY LEE A. WOOLLEY ATTORNE S United States Patent Glitice 3,053,947Patented Sept. 1l., 1962 3,053,947 SEQUENTIAL TIMER .loe Bowman,Greentown, and Lee A. `Woolley, Kokomo, Ind., assrgnors to KingstonProducts Corporation, Kokomoalnd., a corporation of Indiana Filed .lune15, 1959, Ser. No. 820,342 9 Claims. (Cl. 2011-33) This inventionrelates generally to sequential timers, and more specifically to a timerstructure which is adapted to handle a relatively large number ofelectrical circuits.

Although the principles of the present invention may be .included invarious timers, a particularly useful application is made in timers tobe employed in washing machines of the domestic type. In particular, asthe cornplexity of domestic washing machines increases, the cornplex1tyof the electric circuitry thereof also increases. This brings about aneed for a timer structure capable of handling a relatively large numberof circuits. Standing alone, this would appear not to pose a seriousproblem. iI-Iowever, it is ordinarily required that the space occupiedby such a timer be no larger than that occupied by timers constructed tohandle a somewhat lesser number of circuits.

There are manufacturing and flexibility advantages to employing onlysingle-pole switches in such a device. A solution which has previouslybeen considered for the present problem is the use of double-poleswitches. I-Iowever, frequently the circuitry will not admit of suchusage, and the resulting dimensions which must be carefully controlledare vastly increased, thereby rendering the device unduly expensive tomanufacture, coupled with a tendency to have more critical adjustments.

Once the need for an increase in number of switches has been recognized,the structure to be employed to accommodate the same in a single packagepresents numerous problems. For example, for reliability, a certainamount of torque is needed to rotate the sequence cam within the device.It is apparent that as the number of switches to be operated thereby isincreased, the torqueload on the source of power is likewise increased.Thus inthe carrying out of the principal objective, other structural andfunctional problems arise.

The present invention contemplates the utilization of a disc-like camhaving radially spaced cam tracks on both sides thereof which actuatehousing-mounted switches. The switches are proportioned and disposedwith respect to each other so that twenty-four independent circuits canbe handled by the device and governed by the rotation of the sequencecam. The cam is actuated in a step-bystep manner by a drive mechanismwhich is able to handle this number of switches reliably even when amotor of conventional power rating is employed for the purpose. Sincethe number of switches to be aligned precisely with the sequence cam isrelatively large, the device is constructed in such a manner that thesequence cam is axially stationary. However, in response to consumerrequirements, a manual operating shaft is provided Which is axiallyreciprocable with respect to the sequence cam so that the forcesemanating from the various switches do not provide an axial thrust onthe shaft.

Accordingly, it is an object of the present invention to provide asequential timer of an improved construction.

Another object of the present invention is to provide a sequential timercapable of handling a relatively large number of electrical circuits.

Yet another object of the present invention is to provide a novel switcharrangement and disposition within a timer in order that a relativelylarge number of switches may be accommodated in a relatively small spaceor envelope.

A further object of the present invention is to provide a novel drivemechanism for a timer of the type described.

A still further object of the present invention is to provide animproved line-switch actuating mechanism.

Another object of the present invention is to provide improved means forholding a rotatable shaft which is axially slidable in a predeterminedaxial position.

A still further object of the present invention is to provide asimplified structure in a step-by-step timer for obtaining closing of acircuit for a few seconds periodically at an operational rate fasterthan that which the sequence cam is indexed in incremental steps.

Many other advantages, features and additional objects of the presentinvention will become manifest to those versed in the art upon makingreference to the detailed description and the accompanying sheets ofdrawings in which a preferred structural embodiment incorporating theprinciples of the present invention is shown by way of illustrativeexample.

On the drawings:

FIGURE 1 is an elevational View taken edgewise of a sequence timerprovided in accordance with the principles of the present invention;

FIGURE 2 is an elevational View, partly broken away, taken along linelI-II of FIG. 1 when the timer is partially disassembled;

FIGURE 3 is an elevational view taken along line III-III of FIG. 1 whenthe timer is partially disassembled;

FIGURE 4 is an elevational view of a typical sequence cam employed inthe structure of FIG. 1;

FIGURE 5 is an enlarged fragmentary sectional View of a portion of FIG.1; and Y FIGURES 6 and 7 are enlarged fragmentary views, partlydiagrammatic, and partly in elevation, taken adjacent to the shaft ofFIG. 1.

As shown on the drawings:

The principles of this invention are particularly useful when embodiedin a sequential timer or switch mechanism such as is illustrated in FIG.1, generally indicated by the numeral 1li. The switch mechanism includesa housing 11 within which is disposed an intermittently driven sequencecam 12 which operates a series of switches generally indicated in eachof FIGS. 2 and 3 by the numeral 13. As best seen in FIGS. 4-7, thesequence cam is generally flat or disc-like and is provided on eachaxially directed face thereof with a series of radially spaced tracks14. On its periphery, the cam 12 typically is provided with sixtyratchet teeth identified by the numeral 15 so that when the cam isrotated by one tooth, a 6 movement will take place. The sequence cam 12is rotatably mounted in the housing 11 in a manner set forth more fullylater herein. Interconnections may be provided between the variousswitches 13 as desired to adapt this timer device to a particularwashing machine. Likewise, the angular extent of each of the tracks 14is selected to effect the desired control program.

Each of the switches 13 is adapted to be connected into an appropriatecircuit, `as by terminals 16 shown 4in FIG. l. As best seen in FIG. 5,each of the switches 13 includes a pair of contacts 17, 18, the contact17 being carried on a relatively stiff support bracket 19, and thecontact 18 being secured to a support means in the form of a flexibleblade having a movable por-tion 2t). The contact .bracket 19 and themovable blade are secured as by riveting to one of the halves of thehousing 11. Each of the switches 13 is provided with a movable camfollower 21, in this embodiment comprising an angularly or axiallydirected ear secured to the movable blade portion 20. Each of the camfollowers 21 engages one of the tracks 14 so that each of the :3switches 13 is opened and closed in response to rotation of the cam 12.

The housing 11 comprises two halves 11a and 11b, each of which has aconfiguration complemental to the other so as to deline a uniiiedhousing when one is superposed on the other. The housing halves 11a and`11b are held together by a series of resilient spring clips 22 shown inFIG. 1.

with the shaft have been released, the housing halves may be separated,and the interior of the switch mechanism viewed as shown in FIGS. 2 `and3. It will be noted that the various cam followers 21 supported by thehous ing half :11b are each spaced from the rotational Iaxis of the cam12 by a different distance from that which other cam followers on thesame side of the cam 12 are spaced from the rotational axis. It is alsoto be noted that each of the cam followers is thus directed generallyaxially of the sequence cam 12.

In like manner, the various cam followers 21 which are supported Iby thehousing half 11a, are also spaced from the rotational laxis of the cam12 by a distance which differ-s from the spacing of lthe other camfollowers on the same side of the cam 12. In this embodiment, there aretwelve such cam followers carried by each of the housing halves 11a,11b, and the cam 12 therefore has a like number of tracks 14 on eachside thereof -for cooperation with each of the cam followersindividually.

In each of the housingr halves 11a, 11b, the switches 13 are arranged inthe form of `four quadrants. It will be noted that the cam Ifollowers 21of each of the quadrants defines a `generally radial line of engagementwith the tracks 14. Thus, on each side of the cam 12, there are fourradial lines of engagement, each spaced from adjacent lines by about 90.As best seen in FIG. 5, the radial lines of engagement on one side ofthe cam 12 are substantially aligned with the radial lines of engagementon the opposite side of the cam 12.

The housing half 11b, as 'best seen in FIG. 2, is provided with fourabutment means 23, each of which is disposed adjacent to the outer endof the lines of engagement defined by the cam followers 21. The abutmentmeans 23 jointly define a plane which is adjacent to the peripheralportions of one side of the cam, and which plane is normal to therotational axis of the sequence cam 12. A spring 24 is disposed betweenthe housing half 11a and the cam 12, which spring urges the cam 12axially lagainst the abutment means 23. The strength of the spring is`such that for any combination of switches, for example if all of theswitches adjacent to one of the abutment means 23 were so positioned asto apply a maximum opposing force to the spring 24, the spring 24 willnevertheless hold the cam 12 yagainst each of the abutments 23. Thus thespring 24 insures that the cam 12 is always in an axially fixed positionregardless of the combination of switches 13 which may be opposing thespring 24.

Adjacent to each of the abutment means 23, the case has a portion orshoulder which extends toward the viewer in FIG. 2 and indicated at 25.The distance between two opposite shoulders 25 is slightly greater thanthe diametral distance across the teeth of the cam 12. The shoulders 25`and the abutments 23 in combination with the spring 24 thus jointlydene structure for rotatably supporting the cam 12, irrespective of anyother supporting structure which may be included.

In order to effect incremental periodic rotation of the cam 12, theswitch mechanism 10 includes a conventional motor 26, which drives apinion 27 thro-ugh ya gear train. The pinion 27 meshes with and drives amotor-driven gear-cam 28 which is rotatably supported on a pin 29secured to the housing part 11b. The pin 29 is radially offset from therotational axis of the sequence cam 12. The motor-driven cam 28 has twoaxially spaced peripheral cam tracks indicated at 3) and 31. Anintermittent drive mechanism generally indicated at 32 is pivotal- Whenthe clips 22 have been removed, and' other holding means yet to bedescribed and associated ly supported on a pin 33 secured to the housingpart 11b. More specifically, the drive mechanism 32 includes a lever 34having two arms. @ne arm 34a has an outer or free end 35 which isengageable with the cam track 30 of the motor-driven cam 28, which trackis operative to pivot the lever 34 by engaging the end 35, so as to rockthe lever 34 about -an axis which is parallel to and oiset from the axesof both of the cams 12 and 23. The torsion spring 36 acts between thelever 34 and the case 11b to resiliently bias or urge the lever 3d in acounterclockwise direction as viewed in FIG. 2, whereby when the camtrack 3@ engages the end 35 of the lever 34 the lever will returnablyyield in response to such engagement,

The other arm 34b of the lever 34 extends toward the sequence cam 12,terminating adjacent to the periphery thereof. A dog 37 is pivotallysupported on a pin 3S disposed at the distal end of the arm 31th. Thedog has a tooth engaging portion 39 and an abutment portion 4t). Aspring 41 acts between the dog 37 and the arm 34b to provide a clockwisetorsional bias `about the axis of the pin 38` to urge the tooth engagingportion 39 into driving engagement with one of the ratchet teeth 15.When the lever 34 is rotated by the cam track 3% in a clockwisedirection, the adjacent tooth cams the dog 37 in a counterclockwisedirection until the tooth engaging portion 39 slips off the tooth, andmoves clockwise under the influence of the spring 41 to engage the nexttooth. When the end 35 of the lever 34 reaches a precipitous drop 42a,the lever 34 moves in a counterclockwise direction under the iniiuenceof energy stored in the spring 36, thereby positively driving the dog 37into engagement with one of the teeth 15, and also eifecting a clockwiserotation of the sequence cam by an angular amount equalling that definedby the tooth just driven. Thus the sequence cam 12 is caused to rotatein discrete increments in one direction, or lin a step-bystep manner.The rotation of the sequence cam 12 in each increment is terminated whenthe abutment portion 40 of the dog 37 strikes a stop 42 comprising apart of the case or housing half 11b.

It is apparent that since the intermittent drive mechanism 32 is stoppedin its counterclockwise movement by the stop 42, only the dimensionbetween the stop or abutment portion iti and the tooth engaging portion39 of the dog 37 needs to be accurately controlled to get the properamount of movement. This is so because the cam track 3() could causeraising of the end 35 by an amount almost sufficient to engage two teethand yet still only one would be driven. Similarly the cam track 30 mayhave a drop greater than needed, and as shown, because the intermittentdrive mechanism is arrested in its movement by the housing half 11b atthe stop 42, whereas the end 35 of the lever arm 34a does not drop tothe bottom or lowest point on the cam track. This structure eliminates asubstantial amount of wear as well as impact deformation, `therebyproviding a structure which is durable and susceptible to long service.Further, the contour of the cam is not critical, and should wear takeplace on the track 3i), this will have no effect on the magnitude of theincremental advance of the sequence cam 12.

To insure that the spring 41 during clockwise movement of the lever 34does not eiiect a counterclockwise movement of the sequence cam 12,rotation direction limiting means 43 are provided. In this embodiment,the means 43 comprises a resilient blade one end of which is carried ina recess or pocket 44 of the housing half 11b, and the other end ofwhich is endwise engageable with successive ratchet teeth 15. A fulcrumpoint 45 insures that the free end of the blade 43 is biased toward thesequence cam 12. Any tendency of the sequence cam 12 to rotate in acounterclockwise direction is therefore opposed by the means 43 which isthereby placed in compression to preclude such movement. In this manner,the limiting means d3 insures one-way driving engagement by the drivemechanism 32. 'In stepby-step operation, the counterclockwise movementof the lever arm y34 is arrested by the means 4t), 42 just after thefree end of lthe blade 43 has slipped off a tooth 1S. It is to beunderstood that the terms clockwise and counterclockwise have been usedherein as terms of reference and not of limitation.

The housing 11 supports two additional sets of contacts, such sets beingidentified by the reference numerals 46 and 50. The contacts 46 aresupported by the housing, one on a relatively stationary bracket 47 andthe other on a movable blade 48 which is connected in series with one ofthe switches 13. A cam follower portion 49 is secured to the blade 48and is engageable with the other came track 31 of the motor-driven cam28. The track 31 includes two switch-opening and two- Switch-closingportions so that the circuit governed by the contacts 46 will be twiceopened and closed during one revolution of the cam 28 which, as seenabove, corresponds Ito the time which the sequence cam 12 remainsstationary in one position. The circuit including the contacts 46 may beused to advantage to regulate periodic sprays or relatively rapid rinsesin a washing machine.

As best seen in FIG. 2, it can be seen that if the sequence cam 12 wererotated manually in a clockwise direction, the dog 37 would yield underthe infiuence of ratchet teeth 15, as would also the blade 4?).Likewise, the blade 43 would preclude manual rotation of the cam 12 in acounterclockwise direction. To effect such rotation, a shaft 51 may beprovided, the shaft 51 having means generally indicated at S2 in FIG. 6for insuring co-rotation between the shaft 51 and the cam 12. The shaft51 is a unitary part which extends through the housing 11, either end ofwhich may be elongated to provide a place to secure a knob (not shown).Adjacent to the shaft 51, suitable mounting means generally indicated atS3 in FiG. 1 may also be provided if desired. As best seen in FIG. 6,the shaft 51 is rotatably supported by the housing in apertures providedin opposite walls thereof. The shaft 51 is axially slidable within thehousing and is also axially slidaole with respect to the sequence cam12. The exact nature of the axially slidable rotational drivingengagement which the shaft has with the cam 12 is a matter of choice.

The shaft 51 is provided with three circumferential grooves, in thisembodiment all disposed on one side of the sequence cam 12. The first ofthese grooves is identified by the numeral S4, and the second and thirdof these grooves are identified by the numerals 55 and 56. The grooves Sand 56 are each defined in part by a cam shoulder as shown in FIGS. 6and 7, each of such cam shoulders being axially directed away from thecam shoulder of the other of the grooves 55 and 56. The contacts Stlfcomprise part of an additional switch supported by the housing part 11b,which switch has a movable blade 57 which may be actuated in eitherdirection to close one portion of the switch. It is apparent that theactuating portion of this switch is movable in a direction generallyparallel to the axis of the shaft 51. To simplify FIG. 2, the details ofthe switch structure having the contacts Si) has been simplied. However,it is apparent from FlGS. 6 and 7 that the contacts St) may be eitheropened or closed by a pushing or pulling force applied to the shaft 51.Thus, as suggested by FlG. 2, either half of the double-pole structureshown in FIG. 6 and FIG. 7 may be omitted. By the proper' omission, thecontacts 56 may be made to close in response to pushing or may be madeto open in response to an axial pushing force applied to the shaft 51.

To transfer the axial force from the shaft 51 to the blade S7 there isprovided a switch actuating lever SS best seen in FIG. 2. The housing11b has an aperture corresponding in size to the cross-sectionalconfiguration of the lever 58 so that one end 59 projects into suchaperture to be pivotally and slidably retained by the housing. The otherend 6i? thereof is the free end which is drivingly engageable with theactuating portion of the blade 57. intermediate the ends 5h and 6d, thelever S8 is provided with a generally C-shaped slot 61, spaced from thepivoted end 59. The opening 62 in the slot is slightly narrower than thediameter of the shaft in the groove 54, so that when the parts have beenforced or snapped together as shown in FIGS. 6 and 7, they will resistbecoming disconnected. Thus as the shaft 51 is moved axially, it appliesa force to an intermediate portion of the actuating lever 5S which, inturn, operates or moves the switch blade 57. A switch which isresponsive to axial shaft movement is typically employed in a washingmachine to be a line switch or a master switch, and therefore isappropriately connected in the circuit, and is not necessarily under thecontrol `of one of the tracks on the sequential cam 14.

Certain structure is provided to hold the shaft 51 in an axial positionwhich has been selected, such structure being generally indicated by thenumeral 63 in FIGS. 6 and 7, and cooperating with the grooves S5, S6 ofthe shaft 51. A Wall in the housing portion 11b is provided with a pairof slotted apertures 64, 65 respectively disposed on opposite sides ofthe shaft 51. The same wall is also provided with a nest or recess 66,at least one of the apertures 64, 65 and the shaft 51 extendingtransversely therethrough. In the bottom of the nest, there is provideda U-shaped spring 67 having a closed end 68 which loops about the`aperture 64, and having resilient iingers extending to the right of theshaft as shown, the resilient fingers being tangentially receivable inthe grooves 55, 56. In FIG. 6, one of the fingers is shown received inthe shaft groove S5 to hold the shaft in a lowered position as shown,While in FIG. 7 the same linger is received in the shaft groove 56 tohold the shaft 51 in a raised position. The force of the spring fingeris suicient to insure that the blade 57 will be positively held into orout of closed position, as desired. Tlhe lingers of the U-shaped spring67 are yieldable radially of the shaft, toward and away from the viewer,in response to engaging the cam shoulder of either of the `grooves 55,56 during axial shaft movement. A web 69 extends between the fingers ofthe spring, and is integral with the wall of the housing 11.

To hold the spring 67 in substantially fixed position, a spring retainermember 76 is disposed within the housing and within the nest 66. Thespring retainer member 76 comprises a flat apertured portion thro-ughwhich the shaft 51 extends, which portion is engageable iiatwise withthe U-shaped spring 67 to hold it in the nest 66. From each end of theflat apertured portion, there is an ear 76a which respectively extendsthrough one of the slotted apertures 64, 65. A portion of each of theears 76a thus extends thnough the wall outwardly of the housing 11, suchoutwardly extending portion being twisted to prevent withdrawal of thespring retaining member 70. To disassemble the device as previouslydescribed, in addition to release of spring clips 22, it is necessarythat the ears 76a be straightened or untwisted to permit theirwithdrawal into the housing.

From the foregoing, the operation of the sequential timer is nowapparent. When the motor 26 is energized it causes the cam 28 to bedriven at a continuous rate, thereby cycling the spray switch contacts46. Rotation o-f the cam 28 also effects a gradual storage of energy inthe spring 36 when the cam track Sti drives the lever 34 in a clockwisedirection, such energy being released periodically yby a cam drop toeifect an incremental angular advance of the sequence cam 12 driven bythe drive mechanism to a predetermined point determined by the structureof the case. The various rises and falls of the different cam tracks 14are so disposed as to be located approximately midway during suchtravel, although staggering of the ends which effect cam rises may alsobe done under penalty of working to closer dimensions. Thus each of theswitches i3 is rapidly opened or closed in response to the high-speedincremental advances of the sequence cam l2. The cam i?. may not berotated either by the drive mechanism -or by manual means in an oppositedirection because of the effect of the blade 43. However, both the drivemechanism and the blade 43 permit manual positioning of the sequence camto a selected point of rotation.

The sequence cam is rotatably guided by the case or housing and isbiased by the spring 24 to a fixed axial position regardless of whatcombination of switches i3 may be actuated. The sequence cam shaft l isalso utilized as an axially movable shaft to actuate the line switchblade 57 through the novel switch actuating lever 58, the shaft Si beingprovided with novel structure for holding it in a predetermined axialposition within which the sequence cam may be rotated, there being but asingle shaft.

Upon disconnection of the spring clips 22, and straightening of the ears76a, the device comes apart as shown in FiGS. 2 and 3, the lever 5Sthereby also with a slight force becoming disconnected from the shaft topermit removal of the cam from the shaft 5t.. This type of structurefacilitates the substitution of different program cams. Further, whenthe structure is disassembled to the condition shown in FiG. 2, the cam28 may also be manually removed, the lever 34- being manually held outof the way. This further permits the substitution of a differentstepping or spray `cam 2S.

Although various minor modifications might be suggested by those versedin the art, it should be understood that we wish to embody within thescope of the patent warranted hereon all such embodiments as reasonablyand properly come within the scope of our contribution to the art.

We claim as our invention:

l. A switch mechanism for opening and closing a plurality of circuits inpredetermined sequence, comprising in combination: a housing; adisc-like sequence cam rotatably supported in said housing and having aseries of radially spaced axially directed tracks on an axially diectedface thereof; a series of switches within said housing and eachconstructed to be connected into one of said circuits, each of saidswitches including a movable cam follower biased in a direction parallelto the axis of said sequence cam against one of said tracks, each ofsaid switches being secured to said housing so that the cam followersjointly define four substantially radial lines of engagement with saidtracks, said lines of engagement each being defined by a plurality ofsaid cam followers and being angularly spaced from adjacent lines 0fengagement by about 90; said cam followers each being operative to openand close its switch in response to rotation of said sequence cam; saidhousing having abutment means adjacent to the periphery of saiddisc-like sequence cam at the outer end of each of said lines ofengagement, said means defining a plane adjacent to peripheral portionsof one side of said cam and normal to the rotational cmis thereof; `anda spring acting between said housing and said disc-like cam andcontinually urging said cam axially directly against said abutmentmeans, no matter what combination of said switches are being actuated.

2. A switch mechanism for opening and closing a plurality of circuits inpredetermined sequence, cornprising in combination: a housing; asequence cam rotatably supported in said housing and having a series oftracks thereon; means holding said cam in an axially fixed position; aseries of switches within said housing and each constructed to beconnected into one of said circuits, `each of said switches including amovable cam follower, each of said switches being secured to saidhousing so that the cam followers jointly engage with said tracks toeffect switch operation in response to rotation of said sequence cam; asingle rotatably supported axially slidable shaft carried by saidhousing and having rotational driving engagement directly with saidsequence cam, said shaft having a circumferential groove on one side ofsaid sequence cam; an additional switch carried by said housing, saidswitch having an actuating portion movable in a direction generallyparallel to the axis of said shaft; and a switch actuating lever, oneend of said lever being pivotally retained by said housing and its otherend being free and drivngly engageable with said actuating portion ofsaid additional switch, said lever having an intermediate portionreceived in said shaft groove, whereby said additional switch isactuable in response to axial movement of said shaft.

3. A switch mechanism for opening and closing a plurality of circuits inpredetermined sequence, comprising in combination: a housing; a sequencecam rotatably supported in said housing and having a series of tracksthereon; means holding said cam in an axially fixed position; a seriesof switches within said housing and each constructed to be connectedinto one of said circuits, each of said switches including a movable camfollower, each of said switches being secured to said housing so thatthe cam followers jointly engage with said tracks to effect switchoperation in response to rotation of said sequence cam; a singlerotatably supported axially slidable shaft carried by said housing andhaving rotational driving engagement directly with said sequence cam,said shaft having a circumferential groove on one side of said sequencecam; an additional switch carried by said housing, said switch having anactuating portion movable in a direction generally parallel to the axisof said shaft; and a switch actuating lever, one end of said lever beingpivotally and slidably retained by said housing and its other end beingfree and drivngly engageable with said actuating portion of saidadditional switch, said lever having a C-shaped slot spaced from saidone end and snapped onto said shaft at said circumferential groove,whereby said additional switch is actuable in response to axial movementof said shaft.

4. In a switch mechanism having a single shaft r0- tatably supported ina housing for opening and closing a plurality of circuits inpredetermined sequence, said shaft being also axially slidably supportedin the housing for opening and `closing a circuit at any angularposition thereof, the improvement comprising in combination therewith:means in said housing defining a pair of slotted apertures extendingthrough a wall of the housing on opposite sides of the shaft; means insaid housing defining a nest on the inner side of said wall, said shaftand at least one of said slotted apertures extending through said wallat said nest; said shaft having at least one axially directed camshoulder defining a circumferential recess; a spring disposed in saidnest and having at least one resilient finger tangentially receivable insaid shaft recess, said finger being yieldable radially of said shaft inresponse to engagement with said cam shoulder during axial movement ofsaid shaft; and a spring retaining member disposed within said housing,said member having a flat apertured portion slidably receiving saidshaft and engageable with said spring to retain it in Said nest, and anear extending from each end of said flat portion respectively throughone of said slotted apertures, the outer end of each of said ears beingadapted to prevent withdrawal thereof.

5. In a switch mechanism having a single shaft rotatably supported in ahousing for opening and closing a plurality of circuits in predeterminedsequence, said shaft being also axially slidably supported in thehousing for opening and closing a circuit at any angular positionthereof, the improvement comprising in combination therewith: means insaid housing defining a pair of slotted apertures extending through awall of the housing on opposite `Sides of the shaft; means in saidhousing defining a nest on the inner side of said wall, said shaft andat least one of said slotted apertures extending through said wall atsaid nest; said shaft having a pair of circumferentially directedgrooves each defined by an axially oppositely directed cam shoulder andanother shoulder; a generally U-shaped spring disposed in said nesthaving its closed lend extending about said one slotted aperture, andincluding a pair of resilient fingers tangentially receivable in saidgrooves, said fingers being yieldably radially of said shaft in responseto engagement with said cam shoulder of either of said grooves duringaxial movement of said shaft; and a spring retaining member disposedwithin said housing, said member having a fiat apertured portionslidably receiving said shaft and fengageable with said spring to retainit in said nest, and an ear extending from each end of said flat portionrespectively through one of said slotted apertures, the outer end ofeach of said ears being adapted to prevent withdrawal thereof.

6. A switch mechanism for periodically opening and closing a pluralityof circuits in predetermined sequence, comprising in combination: ahousing; a sequence cam rotatably supported in said housing and having aseries of radially spaced axially directed tracks on each axially`directed face thereof, said cam having ratchet teeth on the peripherythereof; a series of switches within said housing and each constructedto be connected into one of said circuits, each of said switchesincluding a movable cam follower biased in a direction parallel to theaxis of said sequence cam against one of said tracks, each of saidswitches being secured to said housing so that the cam followers jointlydefine four substantially radial lines of engagement with said tracks oneach side of said sequence cam, said lines of engagement being spacedfrom adjacent lines on the same side of said sequence cam by about 90,and each being substantially aligned ywith one of the engagement lineson the other side of said sequence cam; said cam followers each beingoperative to open and close its switch in response to rotation of saidsequence cam; said housing having abutment means adjacent to the outerend of each of said lines of engagement defining a plane adjacent toperipheral portions of one side of said cam and normal to the rotationalaxis thereof; a spring acting between said housing and said disc-likecam and continually urging said cam axially directly against saidabutment means, no matter what combination of said switches are beingactuated; a motor-driven cam rotatably supported on said housing inradially offset relation to said sequence cam, and having a peripheral`cam track; an intermittent `drive mechanism pivotally supported by saidhousing and reciprocably driven by said peripheral cam track, saidmechanism including a dog having oneway driving engagement through atooth engaging portion thereof with the peripheral teeth of saidsequence cam to effect incremental advance thereof, said dog also havingan abutment portion; a stop on said housing for engaging said abutmentportion of said dog to define the limit of driving movement of said dogand hence also the limit of Yeach incremental advance of said sequencecam; a single rotatably supported axially slidable shaft carried by saidhousing and having rotational driving engagement directly with saidsequence cam, said shaft having a first circumferential groove on oneside of said sequence cam, and a second and a third circumferentialgroove axially spaced therefrom, said second and third grooves eachbeing dened in part by a cam shoulder axially directed away from the camshoulder of the other of said second and third groove; an additionalswitch carried by said housing, said switch having an actuating portionmovable in `a direction generally parallel to the axis of said shaft; aswitch actuating lever, one end of said lever being pivotally andslidably retained by said housing and its other end being free anddrivingly engageable with said actuating portion of said additionalswitch, said lever having an intermediately disposed C-shaped slotspaced from said one end and snapped into said shaft in said firstgroove for effecting actuation of said additional switch in response toaxial movement of said shaft; means in said housing defining a pair ofslotted apertures extending through a wall of the housing on oppositesides of the shaft; means in said housing defining a nest on the innerside of said wall, said shaft `and at least one of said slottedapertures extending through said wall at said nest; a generally U-shapedspring disposed in said nest having its closed end extending about saidone slotted aperture, and including a pair of resilient fingerstangentially receivable in said second and third grooves, said fingersbeing yieldable radially of said shaft in response to engagement withsaid cam shoulder of either of said second and third grooves duringaxial movement of said shaft; and a spring retaining member disposedwithin said housing, said member having a fiat apertured portionslidably receiving said shaft and engageable with said U-shaped springto retain it in said nest, and an ear extending from each end of saidflat portion respectively through one of said slotted apertures, theouter end of each of said ears being adapted to prevent withdrawalthereof.

7. A switch mechanism for opening and closing a plurality of circuits inpredetermined sequence, comprising in combination: a housing; adisc-like sequence cam rotatably supported in said housing and having aseries of radially spaced axially-directed axially-operative tracks oneach axially directed face thereof; a series of paired contacts; andsupport means, secured -to said housing, for each of said contacts, andconstructed to be connected into one of said circuits, the support meansof one of each pair of contacts having a flat elongated movable portioncarrying the contact and including a cam follower; said support meansbeing arranged on said housing in eight quadrants divided into fourquadrants on each side of said sequence cam with the cam followersthereof directed and biased generally axially of and toward the oppositefaces of said sequence cam, all of said support means on each side lyingin a substantially common plane; each cam follower in each quadrantbeing spaced from the rotational axis of said sequence cam by a distancediffering from that of the corresponding cam followers in the otherthree quadrants disposed on the same side of said sequence cam, said camfollowers jointly defining four substantially radially extendingcoplanar lines of engagement with said tracks on each side of saidsequence cam, the lines of engagement for each of said eight quadrantseach being defined by a plurality of cam followers and being spaced fromadjacent lines on the same side of said sequence cam by about and thefour lines of engagement on one side being substantially aligned withthe four engagement lines on the other side of said sequence cam so thatthe cam followers jointly apply a substantially balanced non-rockingforce to said sequence cam; said cam followers each being operative toopen and close a pair of said contacts in response to rotation of saidsequence cam.

S. A switch mechanism for periodically opening and closing a pluralityof circuits in predetermined sequence, comprising in combination: ahousing; a plurality of switches supported by a portion of said housingand adapted to be connected in said circuits, each of said switcheshaving a cam follower; a `disc-like sequence cam rotatably supported insaid housing, said cam having ratchet teeth on the periphery thereof andhaving a plurality of radially spaced tracks on an axially directed facethereof for engagement with the cam followers of said switches andoperative to open and to close said switches in response to rotation ofsaid sequence cam; a motor-driven cam rotatably supported on saidhousing in radially offset relation to said sequence cam and having aperipheral cam trackgian intermittent drive mechanism pivotallysupported by said housing and reciprocably driven hy said peripheral camtrack, said mechanism including a dog having one-way driving engagementthrough a tooth engaging portion thereof lwith the peripheral teeth ofsaid sequence cam to effect incremental advance thereof, said dog alsohaving an abutment portion; and a fixed stop integral with said switchsupporting housing portion, said stop being abuttable by said abutmentportion of said dog to limit the driving movement of said dog and hencealso to limit the magnitude of each incremental advance of the saidsequence cam to a predetermined angular amount which is independent ofany Wear of said motor-driven cam of said pivotally supported drivemechanism.

9. A switch mechanism for periodically opening and closing a pluralityof circuits in predetermined sequence, comprising in combination: ahousing; a plurality of switches supported iby a portion of said housingand adapted to be connected in said circuits, each of said switcheshaving a cam follower; a disc-like sequence cam rotatably supported insaid housing, said cam having ratchet teeth on the periphery thereof andhaving a plurality of radially spaced tracks on an axially directed facethereof for engagement with the cam followers of said switches andoperative to open and to close said switches in response to rotation ofsaid sequence cam; a motor-driven cam rotatably supported on `saidhousing A111 rad1a1ly oiIset relation to said `sequence cam and having aperipheral cam track; an intermittent drive mechanism pivotallysupported by said housing andrrecipro-A cably driven by said peripheralcam track, said mechanism having one-way `driving engagement with theperipheral teeth of `said sequence cam to effect incremental advancethereof, said mechanism also having an abutment portion; and a fixedstop integral with said switch-supporting housing portion, said stopbeing abuttable by said abutment portion of said pivotal mechanism tolimit the driving movement of said pivotal mechanism and hence also tolimit the magnitude of each incremental advance of said sequence cam toa predetermined angular amount which is independent of any Wear of saidmotor-driven cam or of said pivotally supported drive mechanism.

References Cited in the file of this patent UNITED STATES PATENTS1,726,520 Kramer Aug. 27, 1929 2,482,434 Poole Sept. 20, 1949 2,619,557Illian Nov. 25, 1952 2,680,378 Moe June 8, 1954 2,703,347 ConstantineMar. 1, 1955 2,717,286 Bales Sept. 6, 1955 2,758,166 Aust et al Aug. 7,1956 2,782,271 Jordan Feb. 19, 1957 2,788,850 Leuenberger Apr. 16, 19572,803,715 Gum Aug. 2o, 1957 2,842,627 Wagner July 8, 1958 2,877,317Euler et al. Mar. 10, 1959

